It won’t let me edit pre-existing sims

If you typed in testingcheats on then that is wrong it's testingcheats true then cas.fulleditmode.

@oreosimmer01 Are you on Xbox or PS4? Is the cheat window opening when you press and hold all four shoulder buttons on your controller?

If you are you trying to use the cas.fulleditmode cheat while you are already in CAS I'm not sure it will work. I think you have to enter the cheats first and then go into CAS. In Live Mode, open a cheat window and try using testingcheats true, then enter the cas.fulleditmode cheat, and then go into CAS. Hopefully it works then.

How do I go into CAS? The cheat bar is popping up and I am on ps4. 

@Rachelharris31 , (and @oreosimmer01  & @RandomBuzziness ), actually both testingcheats on and testingcheats true will work. 🤨 They are interchangeable! 🙌  Here is a a full explanation from one of our Champions here 😇  https://sherigr.com/sims-4-cheats/how-to-cheat/#cas

Thank you so much that worked!!!!!!! 😊 

@oreosimmer01 Hey that's awesome! :D

@oreosimmer01 , I'm so happy you got it to work!!! 🙌
Happy Simming! 🥳

That worked for me fortunately, too! My toddler just had a birthday and is a small teen girl with the deepest, most manliest voice I have ever heard!! I needed this cheat to work xD

This is correct! I was using the testingcheats on and it wouldn't work. Tried testingcheats true and it worked again, thank you!